linux-2.6.33/__arm_ioremap_pfn()(arm) の履歴(No.1)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-2.6.33/__arm_ioremap_pfn()(arm) へ行く。
  • 1 (2010-12-02 (木) 14:42:02)

参照元†

• linux-2.6.33/__arm_ioremap_pfn()

説明†

• パス: linux-2.6.33/arch/arm/mm/ioremap.c

• FIXME: これは何？
  • 説明

引数†

• unsigned long pfn
• unsigned long offset
• size_t size
• unsigned int mtype

返り値†

• void __iomem *
  • linux-2.6.33/__iomem

参考†

実装†

/*
 * Remap an arbitrary physical address space into the kernel virtual
 * address space. Needed when the kernel wants to access high addresses
 * directly.
 *
 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 * have to convert them into an offset in a page-aligned mapping, but the
 * caller shouldn't need to know that small detail.
 *
 * 'flags' are the extra L_PTE_ flags that you want to specify for this
 * mapping.  See <asm/pgtable.h> for more information.
 */
void __iomem *
__arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
		  unsigned int mtype)
{
	const struct mem_type *type;
	int err;
	unsigned long addr;
 	struct vm_struct * area;

	/*
	 * High mappings must be supersection aligned
	 */
	if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
		return NULL;

	type = get_mem_type(mtype);
	if (!type)
		return NULL;

	/*
	 * Page align the mapping size, taking account of any offset.
	 */
	size = PAGE_ALIGN(offset + size);

 	area = get_vm_area(size, VM_IOREMAP);
 	if (!area)
 		return NULL;
 	addr = (unsigned long)area->addr;

#ifndef CONFIG_SMP
	if (DOMAIN_IO == 0 &&
	    (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
	       cpu_is_xsc3()) && pfn >= 0x100000 &&
	       !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) {
		area->flags |= VM_ARM_SECTION_MAPPING;
		err = remap_area_supersections(addr, pfn, size, type);
	} else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
		area->flags |= VM_ARM_SECTION_MAPPING;
		err = remap_area_sections(addr, pfn, size, type);
	} else
#endif
		err = remap_area_pages(addr, pfn, size, type);

	if (err) {
 		vunmap((void *)addr);
 		return NULL;
 	}

	flush_cache_vmap(addr, addr + size);
	return (void __iomem *) (offset + addr);
}
EXPORT_SYMBOL(__arm_ioremap_pfn);

コメント†